US expert: Mekong historic drought may caused by China dramatic economic slowdown

Q- How serious do you think the situation is in Vietnam's Mekong Delta?

A-The situation in the Delta is extremely serious regarding drought, the loss of land and intrusion of saline water. The reason is multifaceted, including upstream dams in China and important tributaries including the 3S rivers that trap sediment needed to sustain the Delta against the rising South China Sea and the abuse of the Delta itself from environmentally damaging development activities. These include environmentally destructive irrigation projects, the digging of numerous canals, the removal of sand for sale to Singapore and local development projects, unconstrained investment in aquaculture and the unustainable pumping of fresh water from the aquifer. The susidence of Can Tho, other Delta cities and even HCMC is a bigger factor than the rising South China Sea. Even if no new dams were built on the mainstream and major tributaries the Delta is likely to lose as much of as half of its former land by 2040 or 2050 according to a number of well-regarded experts.

Q - Why are we experiencing these droughts, and what are your predictions for the development of El Nino?

A- El Nino years have long correlated with drought in the Mekong Basin and elsewhere, and this seems true at present, but the Lower Mekong has suffered multi-year periods of extreme drought for more than a decade. Some periods of low water in northern Laos and Thailand have also been linked to the filling of new dams in China's massive six dam Lancang Cascade, starting with the Manwan Dam in 1992-1993. Filling Laos' Nam Theun 2 dam may have also caused reduced dry season flows in the lower reaches of the river in past years.

Q - How about the situation in neighbouring countries like Thailand, Cambodia and Laos?

A- I'm not sure about Laos, but the situation also seems serious in Thailand and Cambodia. Unfortunately, Thailand has begun to divert water in the north.  There is not enough information available to know how important this is or may become.

Q- Why has the water flowing to the Mekong Delta decreased by 50 percent this year? Is it related to the construction of dams?

A- Upstream dams may be a factor, especially in China, as the flow from Yunnan has been said to be the single most important flow during the dry season - perhaps as much as 40 percent in "normal" years. Vietnam and other Lower Mekong neighbors are right to be concerned about the Chinese dams, as the Lancang Cascade can hold more than one-year's average flow into Yunnan from the north.

When China started building the Lancang Cascade, and especially when construction started on the massive Xiaowan Dam, among the world's biggest, it sought to deflect anxieties in the Lower Mekong by saying that because the dams would be generating power throughout the dry season, they would significantly increase the dry season flow all the way to the Delta. Changing the traditional wet-dry seasonal change in the river actually is very damaging to an ecology that has evolved over hundreds of thousands if not millions of years, but downstream countries have generally been much more concerned about flows, not the impact of changing flows on the ecology and environment.

However, China's past assurances did not take into account at least two important possibilities.  The first is climate change.  China has also suffered serious droughts (as well as almost unprecedented floods in recent years).  In most dry seasons China did not increase the dry season flow. Rather, either because of weather conditions or the filling and operation of its dams in Yunnan, the dry season flows at Chiang Saen, near the "Golden Triangle," often have been too low in January and other dry months to reliably support river transport.  China has often been accused of releasing water so that its boats could move upstream to Jinghong without also telling the Thai and Lao shippers and boatmen.

A second factor that may be affecting current flows from China definitely was never foreseen: the dramatic slow-down of the Chinese economy. Electricity consumption in China had no growth in 2015 and may even be declining.

To my knowledge, no one else has mentioned this, but low flows from Yunnan could also be related to low or decreasing demand for electricity. When any dam reduces its power output, it normally does so by taking some turbines off line and closing the relevant gates. China, as any country, would not likely spill water from its reservoir during the dry season, as this would lower the water level and power "head".

Thus it is possible that flows from China are unusually low because the dams are generating less power because of low demand.  Unfortunately, China treats water flows and dam operations as national security secrets.  But when China says, as it has recently, that it will release some additional water, that suggests that it has been holding water back so as not to waste it. China will not share any real time information about the operation of its dams, including water releases, and only provides information about  floods in the wet season. It is not unreasonable to speculate that China's recent announcement that it would release water to alleviate the current drought is timed to coincide with the LMC leaders meeting.

Q - What are your thoughts on Vietnam's efforts to cope with extreme weather in the Mekong Delta in order to support agriculture?

A- There is an expression in English, "We shall have weather, whether or not." All of the plans that I have seen for building dykes against the rising South China Sea and increasingly violent storms seem dubious to many experts and they also are hugely expensive.  In the United States' Mississippi Delta, the ongoing loss of barrier islands and protective wetlands was a major reason why the impact of Hurricane Katrina has prompted the reconstruction and heightening of dykes and sea walls that protect the city and its neighborhoods, but numerous governmental, academic and private sector experts have rejected the idea of building a massive seawall to protect agricultural areas.

Q- What are your recommendations for Vietnam?

A- Of course the Mekong Delta is much more densely populated than the Mississippi Delta and is very critical to the production of rice and aquaculture, but Vietnam should consult extensively with international experts, including the Netherlands, the United States and elsewhere before making a large and dubiously practical commitment to protect the Delta with a seawall and dykes. Urban areas are a different matter, but even here the danger could be reduced by stopping destructive practices such as dredging sand (except to support navigation) and depleting the aquifers. Vietnam should also think carefully about new dams on the Sesan and Srepok rivers, in particular, as these are big sediment trappers.  The sediment is needed by the Delta to keep the sea at bay and by Delta farmers.

Q- How should countries in the Mekong Delta co-operate to maintain sustainable water resources?

A- This is a highly politically sensitive issue, but thus far none of the Lower Mekong countries or China have been willing to give up any of their sovereign rights to promote a truly shared river. In addition, none of the four countries belonging to the Mekong River Commission (MRC) have been willing to give it the authority or political support to carry out it's mission of managing the cooperative, sustainable and equitable development of the Lower Mekong.

Q - As China is not a member of the Mekong River Commission, how should members including Vietnam approach the subject?

A- China is unlikely ever to become a member of the MRC and that probably is a good thing because it's far more powerful than its neighbors and controls the river's headwaters, and has not thus far been inclined to cooperate. As the upstream country, it treats the upper half of the river as a national river, to be done with as it pleases without regard for its neighbors interests.

In 2014 China's five downstream neighbors agreed to a new regional program called the Lancang-Mekong Cooperation  mechanism. Many believe that this was a direct response to the US Lower Mekong Initiative (LMI) comprised of Cambodia, Laos, Myanmar, Thailand, Vietnam and the United States, a 2009 initiative of the then new Obama administration to symbolize a US recommitment to supporting cooperation, stability and sustainable development in Southeast Asia. The only real complaint about the LMI  thus far seems to be that the initiative is insufficiently funded to the aspirations of at least some Lower Mekong countries.

On March 23, China is hosting the first leaders meeting of the LMC mechanism in Sanya, Hainan province. In the words of Xinhua, China's official press organ, "China is expected to provide political guidance and a roadmap for subregional cooperation between China and the five Southeast Asian nations of Cambodia, Laos, Myanmar, Thailand and Vietnam." Sanya is also the headquarters of one of China's most important maritime militias, charged with protecting China's maritime territorial claims to disputed parts of the South China Sea.

In my personal judgment, the most important thing that Vietnam can do at Sanya and after is promote solidarity among the five Lower Mekong countries on insisting to China that the mechanism must primarily be about cooperation on the Mekong.  We are all aware that the major limitation of the ADB-backed Greater Mekong Subregion (GMS) cooperative development initiative, which includes the same membership as the LMC mechanism, is that it is almost entirely about the development of roads and other land-based infrastructure, and does not involve water cooperation or development.  There are obvious reasons for this omission, including the insistence of China, Thailand and probably other countries on sovereign control over their stretch of the shared river.

The first leaders' meeting of the LMC mechanism have in fact been given the theme "Shared River, Shared Future".  This is encouraging if China really intends to provide its downstream neighbors with real time data on the operations of its dams, unusual water releases and the results of its past environmental impact studies.  I personally believe that Vietnam and the other Lower Mekong countries should also insist that the LMC mechanism will truly be about the river, not Beijing's aspirations to bring the LMB into it's "One Belt, One Road" initiative or its plans for the Chinese-initiated Asian Infrastructure Investment Bank (AIIB). Otherwise, Chinese initiative will lack the necessary substance to be of any value to the concerns of LMB countries about what is happening to the Mekong mainstream.